Changes of the local pore space structure quantified in heterogeneous porous media by 1H magnetic resonance relaxation tomography

2001 ◽  
Vol 90 (3) ◽  
pp. 1155-1163 ◽  
Author(s):  
G. C. Borgia ◽  
V. Bortolotti ◽  
P. Fantazzini
Keyword(s):  
Porous Media ◽  
Magnetic Resonance ◽  
Pore Space ◽  
Space Structure ◽  
Heterogeneous Porous Media ◽  
Pore Space Structure ◽  
Resonance Relaxation

Pore-scale Mixing and the Evolution from Anomalous to Normal Hydrodynamic Dispersion

2021 ◽  
Author(s):  
Marco Dentz ◽  
Alexandre Puyguiraud ◽  
Philippe Gouze
Keyword(s):  
Porous Media ◽  
Large Scale ◽  
Molecular Diffusion ◽  
Pore Space ◽  
Breakthrough Curves ◽  
Heterogeneous Porous Media ◽  
Hydrodynamic Dispersion ◽  
Pore Scale ◽  
Sandstone Sample ◽  
Flow Variability

<p>Transport of dissolved substances through porous media is determined by the complexity of the pore space and diffusive mass transfer within and between pores. The interplay of diffusive pore-scale mixing and spatial flow variability are key for the understanding of transport and reaction phenomena in porous media. We study the interplay of pore-scale mixing and network-scale advection through heterogeneous porous media, and its role for the evolution and asymptotic behavior of hydrodynamic dispersion. In a Lagrangian framework, we identify three fundamental mechanisms of pore-scale mixing that determine large scale particle motion: (i) The smoothing of intra-pore velocity contrasts, (ii) the increase of the tortuosity of particle paths, and (iii) the setting of a maximum time for particle transitions. Based on these mechanisms, we derive an upscaled approach that predicts anomalous and normal hydrodynamic dispersion based on the characteristic pore length, Eulerian velocity distribution and Péclet number. The theoretical developments are supported and validated by direct numerical flow and transport simulations in a three-dimensional digitized Berea sandstone sample obtained using X-Ray microtomography. Solute breakthrough curves, are characterized by an intermediate power-law behavior and exponential cut-off, which reflect pore-scale velocity variability and intra-pore solute mixing. Similarly, dispersion evolves from molecular diffusion at early times to asymptotic hydrodynamics dispersion via an intermediate superdiffusive regime. The theory captures the full evolution form anomalous to normal transport behavior at different Péclet numbers as well as the Péclet-dependence of asymptotic dispersion. It sheds light on hydrodynamic dispersion behaviors as a consequence of the interaction between pore-scale mixing and Eulerian flow variability. </p>

Rock-Physics Model of Unconventional Carbonate-Clay Reservoirs with Complicated Pore Space Structure

2019 ◽  
Author(s):  
I. Bayuk ◽  
V. Ryzhkov ◽  
D. Danko ◽  
O. Sivalneva ◽  
A. Shubin
Keyword(s):  
Pore Space ◽  
Rock Physics ◽  
Space Structure ◽  
Pore Space Structure ◽  
Physics Model ◽  
Rock Physics Model
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